Binding of antiparkinsonian ergot derivatives to the dopamine receptor.
The effects of bromocriptine, lisuride and apomorphine on specific binding of 3H-spiroperidol to homogenates of rat caudate nucleus were studied. (+)-Butaclamol was used to define specific binding. Bromocriptine and lisuride inhibited binding markedly, in vitro and also 30 min after in vivo injection. Bromocriptine continued to inhibit binding 24h after a single injection and also after 4 days of drug administration. Lisuride did not affect net specific binding at these periods. Apomorphine produced a mild reduction in binding after 30 min but none after 4 days. It appears that the ergot alkaloids inhibit binding of 3H-spiroperidol by binding strongly to the dopamine receptor.
D000818:Animals; D000978:Antiparkinson Agents / Q000378:metabolism*; D001058:Apomorphine / Q000378:metabolism; D001971:Bromocriptine / Q000378:metabolism; D002421:Caudate Nucleus; D004873:Ergolines / Q000378:metabolism* / Q000494:pharmacology; D008090:Lisuride / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects / Q000378:metabolism*; D013134:Spiperone / Q000378:metabolism
D000978:Antiparkinson Agents; D004873:Ergolines; D011954:Receptors, Dopamine; D001971:Bromocriptine; D013134:Spiperone; D008090:Lisuride; D001058:Apomorphine